1. Field of the Invention
The present invention relates to a process cartridge and an electrophotographic image forming apparatus to which such a process cartridge can detachably be mounted.
The electrophotographic image forming apparatus serves to form an image on a recording medium by using an electrophotographic image forming process, and may be, for example, an electrophotographic copying machine, an electrophotographic printer (for example, LED printer, laser beam printer or the like), an electrophotographic facsimile apparatus or an electrophotographic word processor.
The process cartridge may incorporate an electrophotographic photosensitive member, and a charge means, a developing means or a cleaning means as a cartridge unit, may incorporate an electrophotographic photosensitive member, and at least one of a charge means, a developing means and a cleaning means as a cartridge unit, or may incorporate an electrophotographic photosensitive member and at least a developing means as a cartridge unit, which can detachably be mounted to an electrophotographic image forming apparatus, respectively.
2. Related Background Art
In the above-mentioned process cartridge, when the process cartridge is mounted to the image forming apparatus, a transfer opening through which the electrophotographic photosensitive member is exposed outside is opened, and, when the process cartridge is dismounted from the image forming apparatus, the electrophotographic photosensitive member is covered by a drum shutter to protect the former.
A shutter arm is one of links for opening and closing the drum shutter for light-shielding the photosensitive drum (when the process cartridge is dismounted from the image forming apparatus) and is biased by an elastic body such as a torsion coil spring toward a direction along which the drum shutter is closed. A snap-fit is used to assemble the shutter arm to a frame of the process cartridge.